Influence of Artificial Pinning Centers on Strain Effect in BaHfO 3 -Doped $\mbox{GdBa}_{2}\mbox{Cu}_{3}\mbox{O}_{y}$ -Coated Conductors Fabricated by Pulsed Laser Deposition

The strain dependence of critical current (I c ) on BHO-doped GdBCO-coated conductors (CCs) was evaluated at 77 K in the self-field. The peak strain of I c for the BHO-doped GdBCO CCs shifted toward the compressive strain when compared to the pure-GdBCO CC, and the strain sensitivity of I c in the BHO-doped GdBCO CCs decreased with increasing BHO doping level. To clarify the difference between the strain sensitivity of I c and the peak strain of I c among the CCs, we measured the in-plane lattice parameters of GdBCO layers under tensile loading and estimated the internal lattice strain and the residual strain. As a result, the applied strain dependencies with the internal lattice strain and residual strain were almost the same, in spite of the different BHO doping level. This suggests that the change of the peak strain and the strain sensitivity were not related to the internal lattice strain.